package com.sunnada.edu.system.pub.filter;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
	HttpServletRequest orgRequest = null;

	public XssHttpServletRequestWrapper(HttpServletRequest request) {
		super(request);
		orgRequest = request;
	}

	/**
	 * 覆盖getParameter方法，将参数名和参数值都做xss过滤。<br/>
	 * 如果需要获得原始的值，则通过super.getParameterValues(name)来获取<br/>
	 * getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
	 */
	@Override
	public String getParameter(String name) {
		String value = super.getParameter(xssEncode(name));
		if (value != null) {
			value = xssEncode(value);
		}
		return value;
	}
	
	/**
	 * 
	 * @param name
	 * @return
	 */
	public Object getAttribute(String name) {
		Object value = super.getAttribute(name);
		if (value instanceof String) {
			value = xssEncode(String.valueOf(value));
		}
		return value;
	}

	/**
	 * 
	 * @param name
	 * @return
	 */
	public String[] getParameterValues(String name) {
		String[] values = super.getParameterValues(name);
		if (values != null) {
			for (int i = 0; i < values.length; i++) {
				values[i] = xssEncode(values[i]);
			}
		}
		return values;
	}
	
	/**
	 * @return
	 */
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public Map getParameterMap() {
		HashMap parameterMap = (HashMap) super.getParameterMap();
		HashMap paramMap = (HashMap) parameterMap.clone();
		for (Iterator iterator = paramMap.entrySet().iterator(); iterator
				.hasNext();) {
			Map.Entry<String, String[]> entry = (Map.Entry<String, String[]>) iterator.next();
			String[] values = entry.getValue();
			for (int i = 0; i < values.length; i++) {
				if (values[i] instanceof String) {
					values[i] = xssEncode(values[i]);
				}
			}
			entry.setValue(values);
		}
		return paramMap;
	}

	/**
	 * 覆盖getHeader方法，将参数名和参数值都做xss过滤。<br/>
	 * 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br/>
	 * getHeaderNames 也可能需要覆盖
	 */
	@Override
	public String getHeader(String name) {

		String value = super.getHeader(xssEncode(name));
		if (value != null) {
			value = xssEncode(value);
		}
		return value;
	}

	/**
	 * 将容易引起xss漏洞的半角字符直接替换成全角字符
	 * 
	 * @param s
	 * @return
	 */
	private static String xssEncode(String s) {
		if (s == null || "".equals(s)) {
			return s;
		}
		StringBuilder sb = new StringBuilder(s.length() + 16);
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			switch (c) {
			case '>':
				sb.append('＞');// 全角大于号
				break;
			case '<':
				sb.append('＜');// 全角小于号
				break;
			case '\'': 
				//sb.append('‘');// 全角单引号  
				break; 
			case '\"': 
				sb.append('“');// 全角双引号
				break;
			case '&':
				sb.append('＆');// 全角
				break;
			case '\\':
				sb.append('＼');// 全角斜线
				break;
			case '#':
				sb.append('＃');// 全角井号
				break;
			default:
				sb.append(c);
				break;
			}
		}
		String str = sb.toString();
		str = replaceBlank(str);
		str = replaceAll(str, "javascript:", "");
		str = replaceAll(str, "jscript:", "");
		str = replaceAll(str, "vbscript:", "");
		str = replaceAll(str, "script:", "");
		str = replaceAll(str, "select:", "");
		str = replaceAll(str, "document:", "");
		str = replaceAll(str, "cookie:", "");
		str = replaceAll(str, "alert:", "");
		
		return str;
	}

	/**
	 * 去 空白符
	 * @param source
	 * @return
	 */
	public static String replaceBlank(String source) {
		Pattern p = Pattern.compile("\\s*|\t|\r|\n");
		Matcher m = p.matcher(source);
		return m.replaceAll("");
	}

	/**
	 * 替换字符串 ；大小写不敏感
	 * @param source
	 * @param oldStr
	 * @param newStr
	 * @return
	 */
	public static String replaceAll(String source, String oldStr, String newStr) {
		return source.replaceAll("(?i)" + oldStr, newStr);
	}

	/**
	 * 获取最原始的request
	 * 
	 * @return
	 */
	public HttpServletRequest getOrgRequest() {
		return orgRequest;
	}

	/**
	 * 获取最原始的request的静态方法
	 * 
	 * @return
	 */
	public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
		if (req instanceof XssHttpServletRequestWrapper) {
			return ((XssHttpServletRequestWrapper) req).getOrgRequest();
		}
		return req;
	}
}